refactor(auth): use API base URL directly for OIDC endpoints

Remove SECUIRD_OIDC constant that stripped /api/v1 from the base URL.
OIDC endpoints are now served under the API path directly.

src/pages/auth/LoginPage.tsx

@@ -28,7 +28,6 @@ import { OAuthProvider } from "@/lib/oauth";
 type LoginStep = 'credentials' | 'totp' | 'webauthn' | 'passkey-email' | 'mfa-enrollment' | 'mfa';
 
 const SECUIRD_API = import.meta.env.VITE_API_BASE_URL ?? 'http://localhost:5000/api/v1';
-const SECUIRD_OIDC = SECUIRD_API.replace(/\/api\/v1\/?$/, '');
 
 /**
  * Complete an OIDC authorization flow after the user has authenticated.
@@ -36,7 +35,7 @@ const SECUIRD_OIDC = SECUIRD_API.replace(/\/api\/v1\/?$/, '');
  * the auth code and returns the redirect URL for the calling application.
  */
 async function completeOidcFlow(oidcSessionId: string, token: string): Promise<string> {
-  const res = await fetch(`${SECUIRD_OIDC}/oidc/complete`, {
+  const res = await fetch(`${SECUIRD_API}/oidc/complete`, {
     method: 'POST',
     headers: { 'Content-Type': 'application/json' },
     body: JSON.stringify({ oidc_session_id: oidcSessionId, token }),